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RC1 87  .D85  Typhoid  fever  and  it 


RECAP 


' 


Columbia  Sanitiersfftp 

College  of  ^ijpsiciaits!  anb  ^urfleons 
Hitirarp 


Typhoid   Fever  and 
Its   Sequelae 


Read    before    the    Section    on    Vital    Statistics, 

American     Public    Health    Association, 

Jacksonville,   Fla.,    December,    1914 


BY 

LOUIS  I.  DUBLIN,  Ph.D.,  Statistician 

Metropolitan  Life  Insurance  Company,  New  York 

1914 


Digitized  by  tine  Internet  Arciiive 

in  2010  witii  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/typhoidfeveritssOOdubl 


TYPHOID  FEVER  AND  ITS  SEQUELAE. 

Our  problem  in  this  study  was  to  measure  the  effect  of  typhoid  fever 
upon  vitality  during  the  first  three  years  following  recovery,  and  also  to 
note  the  causes  of  death  which  predominate  during  this  period. 

Records  Used. 

For  this  purpose,  we  turned  to  the  reports  of  the  Visiting  Nurse  Service 
of  the  Metropolitan  Life  Insurance  Company  for  the  year  1911.  In  that 
year,  1,936  cases  of  typhoid  fever  were  recorded.  A  fairly  complete  record 
of  the  illness  in  these  cases  was  available.  A  further  advantage  in  this 
series  was  the  fact  that  the  subsequent  whereabouts  and  condition  of  those 
who  were  treated  could  be  obtained  from  the  insurance  records.  In  this 
way,  we  could  at  once  be  informed  with  regard  to  the  present  status  of  these 
persons;  whether  they  were  living  or  dead,  the  date  of  death,  as  well  as  a 
complete  record  of  the  conditions  at  death  in  these  later  cases.  It  was,  in 
other  words,  possible  for  us  to  trace  this  series  fairly  completely  and  to 
determine  the  consequences  and  effects  of  typhoid  fever  on  these  persons. 

An  examination  of  our  1,936  cases  led  to  the  elimination  of  362  in  which 
the  record  did  not  appear  satisfactory  from  the  point  of  view  of  accu- 
racy of  diagnosis.  As  a  result,  we  had,  after  careful  analysis,  a  residue 
of  1,574  cases.  All  of  these  presented  satisfactory  evidence,  so  far  as  such 
records  alone  could,  that  the  patient  had  suffered  from  an  attack  of  "ty- 
phoid fever"  at  the  time  of  1911  nursing.  The  cases  were  in  the  hands  of 
physicians  and  nurses.  The  treatment  of  the  disease  in  every  case  indi- 
cated typhoid  fever.  The  duration  of  the  service  as  well  as  the  large  num- 
ber of  visits  made,  all  pointed  conclusively  that  our  series  was  well  selected 
and  sound.  The  average  number  of  visits  made  per  case  by  our  Visiting 
Nurse  Service  to  these  patients  was  close  to  seventeen  (16.85)  and  the  dura- 
tion of  nm-sing  was  close  to  twenty-four  (23.87)  days. 

Distribution  by  Age  axd  Sex. 
Table  1  shows  the  distribution  of  the  1,574  cases  by  age  and  sex.  It 
will  be  noted  at  once  that  70.3  per  cent,  of  the  total  cases  were  under  twenty 
years  of  age  and  that  34. 1  per  cent,  were  under  ten  years.  This  proportion 
is  somewhat  higher  than  that  usually  observed  in  other  typhoid  fever  series. 
The  explanation  Hes  in  the  fact  that  our  Visiting  Nurse  Service  is  more 
readily  availed  of  by  women  and  children.  It  is  important  also  to  remem- 
ber this  large  incidence  at  the  earlier  ages  in  view  of  its  bearing  on  our  find- 
ings later  with  reference  to  the  sequelee. 


TABLE  1. 
DISTRIBUTION  BY  AGE  AND  SEX  OF  1,574  CASES  OF  TYPHOID  FEVER. 

Visiting  Nitrse  Service,  1911,  Metropolitan  Life  Insurance  Company. 


Age  period. 


Males  and  females. 

Number. 

Per  cent. 

536 

34.1 

570 

36.2 

230 

14.6 

114 

7.2 

81 

5.2 

43 

2.7 

Males. 


Females. 


Under  10 

10-19 

20-29 

30-39 . 

40-49 

50  and  over . 

Total — all  ages ,      1,574 

I 
Per  cent,  of  total — by  sex I 


251 
254 
85 
35 
23 
17 


285 

316 

145 

79 

58 


100.0 


665 


909 


100.0 


42.3 


57.7 


Lethal  Rates. 

Table  2  presents  the  lethal  rate  per  100  treated  for  each  period.  The 
least  rate  is  that  for  the  children  under  ten;  the  highest  trustworthy  rate 
is  for  the  group  20-29  which  was  13.91  per  100.  At  the  higher  ages  there 
are  too  few  exposed  to  make  the  rate  dependable.  For  the  entire  series 
of  1,574  cases  treated,  the  lethal  rate  was  9.28  per  100  treated.  This  figure 
is  consistent  with  that  of  other  series  which  vary  slightly  above  and  below 
a  mean  of  10  deaths  per  100  cases  treated. 

TABLE  2. 

LETHAL  RATES  PER  100  CASES  TREATED  FOR  TYPHOID  FEVER- 
CLASSIFIED   BY  AGE  PERIOD. 

Visiting  Nurse  Service,  1911,  Metropolit.an  Life  Insurance  Company. 


Age  period. 

Number  treated. 

Number  died 
under  treatment. 

Lethal  rate 
per  100  treated. 

Under  10 

536 
570 
230 
114 
81 
43 

36 
45 
32 
12 
13 
8 

6  72 

10-19 

7  89 

20-29 

13  91 

30-39 

10  53 

40-49 

16  05 

50  and  over 

18  60 

Total — ^all  ages 

1,574 

146 

9  28 

COMPLICATIOXS. 

Table  3  shows  the  complications  in  these  146  cases.  These  are  important 
in  view  of  our  interest  in  the  sequelae  to  be  referred  to  later.  Interest 
should  be  centered  in  the  fact  that  over  15  per  cent,  involve  intestinal  per- 
foration, hemorrhage,  peritonitis  and  other  similar  conditions.  Meningitis 
and  pneumonia  were  present  in  10.3  per  cent,  of  the  fatal  cases,  heart  con- 
ditions in  8.2  per  cent,  of  the  cases.  Other  complications,  such  as  tuber- 
culosis and  acute  nephritis  indicated  that  the  lungs  and  kidneys  were  im- 
paired in  a  considerable  number  of  cases  in  coimection  with  the  typhoid 
infection. 

TABLE  3. 

COMPLICATIONS  IN  146  FATAL  CASES  OF  TYPHOID  FEVER. 

Visiting  Ntikse  Service,  1911,  Metropolitan  Life  Insurance  "CoWany. 


Complications  -nitli  typlioid  fever. 


Number  of 

Per  cent,  of 

deaths. 

total  deaths. 

60 

41.1 

22 

15.1 

15 

10.3 

15 

10.3 

12 

8.2 

8 

5.5 

4 

2.7 

10 

6.8 

146 

100.0 

No  complications  stated 

Intestinal  perforation,  hemorrhage 

Meningitis 

Pnemnonia 

Heart  involvements 

Tuberculosis  (all  forms) 

Acute  nephritis 

Other  compHcations 

Total  fatal  cases 


DlSTRIBUTIOX  OF  RECOVERED    CaSES. 

Table  4  shows  the  distribution  by  age  and  sex  of  the  1,4£8  persons  who 
recovered  from  the  typhoid  fever.  This  distribution  is  very  slightly  dif- 
ferent from  that  of  Table  1  which  showed  the  distribution  of  the  initial 
cases. 

Relation  Actual  to  Expected  Mortality. 

From  this  point  onward,  our  effort  was  directed  to  a  comparison  of  the 
actual  and  expected  mortality  among  the  1,428  survivors.  Our  method 
was  as  follows:  The  1,428  cases  were  distributed  by  sex  and  color  and  by 
ten-year  age  periods.  A  separate  schedule  was  prepared  for  each  sex  and 
color.  The  mortality  rates  of  the  Company  for  each  individual  age.  sex 
and  color  class  was  employed  as  a  standard.     We  assumed  that  the  mor- 

3 


TABLE  4. 


DISTRIBUTION  BY  AGE  AND  SEX  OF  1,428  PERSONS  WHO  RECOVERED  FROM 

TYPHOID   FEVER. 

Visiting  Nurse  Service,  1911,  Metropolitan  Life  Insurance  Company. 


Males  and  females. 

Males. 

Age  period. 

Number. 

Per  cent. 

Females. 

Under  10    

j 
500                  35.0 

239 

232 

68 

30 

14 

9 

261 

10-19                        

525 
198 
102 

36.8 

13.9 

7.1 

293 

20-29 

30-39            

130 

72 

40-49 

68         '           4.8 
35                    2.5 

54 

26 

Total — all  ages 

1,428 

100.0 

592 

836 

Per  cent,  of  total — -by  sex 

100.0 

41.5 

58.5 

tality  actually  experienced  in  1911  by  the  Company  in  the  Industrial  De- 
partment should  serve  as  the  measure  of  the  expected  deaths  for  the  cor- 
responding group  of  these  persons  who  had  recovered  from  typhoid  fever 
in  191 1  for  the  first  year  after  recovery.  For  the  second  year  after  recovery, 
we  employed  similar  mortality  figures  for  the  year  1912  as  a  standard  and 
for  the  third  year  we  employed  the  figures  for  1913.  In  other  words,  the 
mortality  table  used  was  not  an  arbitrary  measure  but  exhibited  the  death- 
rates  which  persons  of  the  same  sex,  color  and  age  among  our  Industrial 
policyholders  actually  experienced.  By  throwing  these  rates  into  the  num- 
ber of  years  of  life  of  each  group  in  successive  years  since  recovery  we 
obtained  the  number  of  expected  deaths  for  each  age  period. 

In  this  way  we  found,  as  shown  in  Table  5,  that  in  the  series  of  1,428 
persons  the  expected  number  of  deaths  was  equal  to  26.45.  As  a  matter 
of  fact,  our  record  showed  54  actual  deaths.  The  ratio  of  actual  to  ex- 
pected deaths  was,  therefore,  for  our  entire  series,  204  per  cent.  In  other 
words,  more  than  twice  the  mortality  expected  was  realized.  You  will 
note  that  the  total  number  of  years  of  life  was  nearly  3,850  years. 

A  number  of  persons  dropped  out,  either  by  death  or  lapsing  their  policies 
during  the  first,  second  or  third  year  after  recovery.  Each  such  exit  from 
our  series  involved  an  adjustment  in  the  number  of  years  of  life  exposed  to 
risk,  by  taking  the  proportionate  part  of  a  year  from  the  date  of  recovery 
to  the  date  of  exit.  In  this  way,  every  day  of  experience  was  used.  For- 
tunately, the  fullness  of  the  Company's  record  made  this  much  desired 

4 


TABLE  5. 


COMPARISON  OF  ACTUAL  AND  EXPECTED  MORTALITY  IN  THREE  YEARS 
FOLLOWIxXG  RECOVERY  FROM  TYPHOID  FEVER— CLASSIFIED  BY  AGE 
PERIOD. 

Cases  The.\ted  by  Visitixg  Nurse  Service,  1911,  Metropolitax    Life  Insurance 

Company. 


Age  period. 

Number  of 
years  of  life. 

Number  of 
expected  deaths. 

Number  of 
actual  deaths. 

Per  cent. 

actual  of 

expected  deaths. 

Under  10      

1,354.15 
1,434.66 

521 . 27 

274.16 

173.05 

92.62 

8.07 
5.61 
3.92 
2.94 

2.46 
3.45 

13 

12 

13 

5 

8 

3 

161 

10-19 

214 

20-29 

30-39 

40-49 

50  and  over 

332 
170 
325 

87 

Total — all  ages .... 

3,849.91 

26.45 

54 

204 

step  possible.  It  would  be  difficult  in  many  other  sendees  to  keep  such 
complete  control  of  the  whereabouts  of  the  indi\aduals  composing  a  large 
series.  Our  conclusion  from  our  own  series  is,  therefore,  that  during  the 
first  three  years  after  recovery  from  typhoid  fever,  the  mortality  is  twice 
the  normal. 

It  is  interesting  to  note,  however,  that  this  increased  rate  is  not  uni- 
formly evident  in  all  the  three  years  of  the  series.  Thus,  in  the  first  year 
following  recovery  from  typhoid  fever  the  ratio  of  actual  to  expected 
deaths  was  284,  in  other  words  nearly  three  times  as  great  as  it  should  be. 
In  the  second  year,  the  percentage  actual  of  expected  deaths  was  217,  and 
in  the  third  year  it  fell  below  the  expected,  namely  to  80  actual  deaths  per 
100  expected  deaths.  This  last  fact  is  puzzKng.  A  careful  reexamination 
was  made  of  our  series.  No  effort  was  spared  in  finding  a  possible  source 
of  error  and  yet  at  the  very  end,  we  find  no  evidence  of  an  additional  death 
which  would  in  any  way  change  our  figure. 

It  would  appear  from  our  figures  that  typhoid  fever  has  its  impairing 
effect  in  the  first  two  years  after  recovery.  It  would  seem,  although  we 
would  not  press  this  explanation,  that  the  weakhngs  had  been  eliminated  by 
the  immediate  deaths  and  those  that  followed  in  the  first  two  years  after 
recovery.  Table  7  shows  the  causes  of  death  in  the  54  cases  that  occurred 
in  the  three  years  subsequent  to  recovery.  Tuberculosis  heads  the  list  with 
twenty-one  deaths  (39  per  cent.),  of  which  aU  but  three  cases  were  of 
the  pulmonary  type.  The  second  important  group  are  the  diseases  of  the 
heart  with  a  total  of  eight  cases.  Pneumonia,  and  kidney  disease  follow 
with  four  cases  each. 


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Our  conclusion,  then,  from  this  table  is  that  the  incidences  of  tuberculosis 
and  the  diseases  of  the  heart  are  increased  subsequent  to  typhoid  fever. 
This -is  borne  out  by  the  previous  statement  of  complications  which  oc- 
curred in  the  immediate  deaths,  Table  3,  where  a  considerable  number  of 
cases  showed  heart  and  pulmonary  complications.  This  condition  has 
been  noted  consistently  by  other  observers  of  typhoid  fever  and  its  sequelae. 

Effect  of  Sequels  upon  General  Death  Rate. 

We  will  close  this  paper  with  an  estimate  of  the  effect  of  typhoid  fever 
upon  mortality  in  the  three  years  subsequent  to  an  attack.  On  the  basis  of 
the  estimated  population  of  Continental  United  States  in  1914,  we  have 
calculated  that  each  year  a  minimum  of  close  to  8,000  deaths  occur  which 
can  be  attributed  annually  to  the  impairments  which  follow  typhoid  fever. 
In  this  estimate,  we  have  assumed  a  minimal  death-rate  from  typhoid  fever 
of  20  per  100,000.  We  have  also  assumed  the  number  of  cases  to  be  ten 
times  as  great  as  the  number  of  deaths  in  accordance  with  the  usual  practice. 
The  number  of  recoveries,  therefore,  is  90  per  cent,  of  the, cases.  For  each 
of  the  three  years  following,  we  have  assumed  an  expected  death-rate  for 
the  entire  country  to  be  at  least  15  per  1,000  from  aU  causes.  A  calcula- 
tion of  the  additional  deaths  due  to  sequelse  of  typhoid  fever  gives  us  a 

TABLE  7. 

CAUSES  OF  5i  DEATHS  IN  THREE  YEARS  FOLLOWING  RECOVERY  AMONG 
1.428   CASES  OF  TYPHOID  FE^^ER. 

Treated  By  Visiting  Ntjese  Service,  1911,  Metropolitan"^  Life  IssuRAisrcE  Company. 


Cause  of  death. 


Number  of  deaths.       Per  cent,  of  total  deaths. 


Tuberculosis: 

Pulmonary 

Other  forms 

Diseases  of  the  heart: 

Endocarditis 

Myocarditis 

Valvular  disease  of  the  heart . 

Pneumonia 

Nephritis : 

Acute 

Bright's  disease 

Acute  articular  rheumatism.  .  . 

Violent  causes 

Other  causes 

Total — all  causes 


18 

33.3 

3 

5.6 

4 

7.4 

2 

3.7 

2 

3.7 

4 

7.4 

1 

■    1.9 

3 

5.6 

2 

3.7 

7 

13.0 

8 

14.8 

54 

100.0 

total  of  7,781.  This  is  the  price  that  is  paid  annually  over  and  above  the 
registered  direct  loss  from  typhoid  fever  according  to  the  results  of  our 
study.  It  is  not  only  the  £0,000  immediate  deaths  that  we  have  to  con- 
sider, but  the  additional  8,000  who,  although  recovered,  cannot  sur\nve 
the  strain  which  modern  industrial  life  makes  necessary  and  who  either 
because  of  tubercular  or  cardiac  lesions  die  untimely  deaths  within  the 
first  or  the  second  year  after  recovery. 

TABLE  8. 

ESTIMATED  NUMBER  OF  DEATHS  TO  BE  ATTRIBUTED  ANNUALLY  TO 
SEQUELS  OF  TYPHOID   FEVER  IN  THE   LuS^ITED   STATES. 

Population,  Continental  United  States,  1914 98,781,324 

Typhoid  Fever:                                                                                          "  * 

Death  rate  per  100,000,  Continental  United  States,  1914  (minimal  estimate) ...  20 

Deaths  in  United  States  in  1914 19,800 

Cases  in  United  States  in  1914 198,000 

Recoveries,  each  year,  in  United  States 178,200 

Extra  deaths  to  be  attributed  annually  to  sequelae  of  typhoid  fever.     (On  basis 

of  double  mortality  in  three  years  following  recovery) 7,781 


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